Study On Bonding Interfacial Performance And Enhancement Technology Of Hypertonic Sandstone Layer

Cementing interface cementation is the key to affect the sealing effect, the interface bond quality is directly related to development benefit. After the long-term development of sandstone water injection reservoir, the formation water washing is serious, the water cut rate is rising, and the interface cementation of high permeability sandstone reservoir is very prominent. Through the experimental study on the acoustic response and mechanical properties of cementing interface in high permeability sand stratum,the main factors affecting the cementing quality and the mechanism of deterioration are studied; Through the research and development of interface strengthening technology,improve the interface bonding state,and futher improve the quality of cementing,which has an important significance for the development of water injection reservoir. Through the comprehensive system research, the paper has made some of the following results.The study of high permeability sandstone interface acoustics was done. The experiment installation and evaluation method for the interfacial shear strength and hydraulic seal isolation is established under the condition of downhole temperature and fluid flow. Through experiments, the amplitude of the first wave of the wave is increased with the increase of the permeability of the formation, at the same time, the dynamic environment of the underground has increased the amplitude of the first wave. Therefore, the high permeability and erosion corrosion of formation fluid are the main factors that affect the acoustic response of the permeable layer. Adopting cylindrical multilayer open acoustic duct model and establishing numerical stimulation software, simulation calculation of interfacial bond of high permeability sandstone layer and the physical simulation results are verified and predicted.The study of high permeability sandstone interface mechanical properties was done.Equipment and method for measuring the interfacial shear strength and hydraulic sealing capacity of the downhole temperature and fluid flow are established.The experimental results show that with the increase of the formation permeability, the interfacial shear strength and hydraulic sealing ability are lower, and the dynamic environment is lower than the static environment.Based on the results of the research on the mechanical properties and the acoustic response of the interface, the relationship between the cementation index and the hydraulic sealing ability is established, and the method of evaluating the hydraulic sealing ability of the cement sheath is formed, which can provide technical support to the development scheme.The microstructure of the interface Cementation of the high permeability sandstone layer was analyzed.Compared with mudstone layer, the interface microstructure of Casing cement ring interface of high permeability sandstone is loose,and the interface is weak, and under thedynamic environment, the partial Ca(OH)2 is dissolved in the erosion of the formation fluid.Based on the microstructure analysis and mechanical properties testing,the interfacial transition zone of the casing cementing sheath in the high permeability sand layer was found,and the structure model of three types of casing cement sheath interface,which is the base type of mudstone,sandstone load type and sandstone environment type is constructed.The interfacial enhancement technology of high permeability sandstone layer was studied.In this paper, we put forward two ways to improve the strength of mud cake and reduce the water erosion product in oil well cement.Using technology of promoting mud cake solidification, crystallization catalysis,Corrosion permeability, etc, the enhanced drilling fluid treating agent and cement slurry is developed, and the application of field application has achieved good results.